About the Orthographic Projection
The Orthographic projection is another ancient azimuthal projection. Hipparchus used it in the 2nd century BC to determine places of star-rise and star-set. The Roman architect, Marcus Vitruvius Pollio, used it in about 14BC to construct sun dials and compute sun positions.
The Orthographic projection is a parallel projection onto a tangent projection plane. This is equivalent to a perspective projection viewed from infinity (ie. similar to a real world view from a neighboring star system). This is very similar to the Near-Sided Perspective projection but with a height of infinity.
The Orthographic Projection is not conformal. Distortion is minimal at the center, but increases to a maximum at the edges as the area and distance scales decrease to zero.
See our interactive Orthographic Projection Northern Hemisphere map.